Present day practices in crop harvesting involve the formation of bales of crop material such as hay or the like into stacks for storage by the employment of an automatic bale wagon. One type of bale wagon for use in this manner, which has achieved wide spread commercial acceptance, is the automatic bale wagon which employs the three table concept as originally illustrated and described in U.S. Pat. No. 2,848,172 issued to Gordon E. Grey.
The Grey bale wagon includes a first table which receives bales from a bale loader or pick up device mounted on the bale wagon, and accumulates a predetermined number of these bales on this first table, for example two, the bales being arranged thereon end-to-end in a row. A second table successively receives the accumulated rows of bales from the first table and accumulates a plurality of such rows, for example four, five or six rows, which plurality of rows is commonly known as a tier of bales. A third table or load bed successively receives the tiers from the second table and accumulates a plurality of these tiers, for example seven, to form a stack thereon. Once the stack has been accumulated on the load bed, it may be unloaded by pivoting the load bed 90.degree. and depositing the stack on the ground or the like so that the first tier of bales which was accumulated on the second table is now the lowermost tier of the stack in contact with the ground surface.
The Grey bale wagon deposited all of the bales in such a manner that the tiers were formed with all bales laying on their edge sides so that the bales forming the lowermost tier are oriented such that a non-twine or -wire bearing side of each bale, commonly refered to as an "edge" of the bale, is in contact with the ground in order to avoid wire rusting or twine rotting which eventually would result in broken bales in the lowermost tier and would probably cause toppling of the stack.
In order to enhance the stability of the stack, it is desirable to provide one or more tie tiers within the stack, such being tiers having individual bales arranged to overlap two bales in adjacent tiers above and below the tie tier. Formation of one or more of such tie tiers can be accomplished during formation of the stack on the bale wagon, for example through utilization of a mechanism which is similar to that illustrated and described in U.S. Pat. No. 3,395,814, which has been incorporated into several present day commerical models of the Grey bale wagon.
U.S. Pat. Nos. 3,945,507 to James A. Olsen et al and 3,927,771 to Lee D. Butler et al; the specifications of which are incorporated herein by reference, relate to improved bale wagons for facilitating the formation of a block-type stack on the wagon, and particularly, these improvements facilitate tier pattern selection and formation on the wagon as well as formation of bales into a predetermined sequence of tier patterns to form a block.
The Olsen et al and Butler et al patents disclose an improved arrangement whereby bales may be placed selectively either "on edge" or "on flat" on the second table so that the appropriate tier pattern may be formed in the proper position as the stack is being formed on the wagon. The wagon utilizes a mechanical memory system incorporating a multi-lobed rotatable cam and follower, the cam lobes defining a plurality of positions representing one of the tier patterns.
A plurality of sensors are provided on the second table of the bale wagon in the form of paddles which are depressed when a bale is placed on the paddle, thus indicating the position of the bale on the table. Means are provided for responding to the addition of each of the tiers of bales to advance the cam to the next position for forming the next tier in the proper configuration.
This system represented a significant improvement in bale wagons in that it relieved the operator of the necessity of remembering the particular stack patterns he wanted to build and of constantly counting the tiers as they were formed and deposited on the load bed and actuating the appropriate mechanisms for forming the tie tiers.
One disadvantage, however, of this bale wagon was the complexity of the mechanical and hydraulic systems for controlling the various operating modes and functions, and controlling the hydraulic actuators therefore. The more operational modes built into such a system, the more complex are these mechanical and hydraulic actuator mechanisms, which can in turn lead to more costly repairs and more extensive service time when the equipment suffers a breakdown. Additionally, the more complex the mechanical and hydraulic interconnections, the more costly is the overall piece of apparatus.
Accordingly, it is a primary object of the present invention to provide an improved control system for a bale wagon which may be described as electro-hydraulic in nature.
A further object of the present invention is to provide a control system for a bale wagon which is more reliable than prior art control systems and has fewer maintance and related problems.